The authors studied sixty-nine psychopathic personalities with the electroencephalogram and with personality studies. They distinguished five distinct clinical pictures. Two of the groups had particular types of electroencephalographic abnormalities. To this reviewer, differentiating between 'psychopathic personalities with poor ethical standards', 'psychopathic personalities with loose organization of personality', 'psychopathic personalities with a generally inadequate type of personality', etc., does not seem to establish any clear-cut clinical pictures.